Boiler and furnace



Nov. 17, 1931. G. P. JAcKsN BOILER AND FURNACE Filed June 15, 1927 ATTORNE NVENTOR Patented Nov. '17, .1931

`UNITE!) STATES l PATENT OFFICE GEORGE '.P.I JACKSON, 0F FLUSHING, NEW YORK, ASSIGNOR TO INTERNATIONAL COM'B'USTION ENGINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION or DELAwAnE Application led June 15,

This invention relates to improvements in boiler and furnace, particularly where fuel in a finely divided form, such as powdered coal, is to be burned in space for the generation of the steam.

One of the primary objects of the invention is to provide an improved arrangement or combination of boiler and furnace in which the pulverized coal is admitted horizontally.

Another object of the invention is to provide for improved circulation in a boiler fired by a furnace lined with water tubes.

More specifically it -is an obgect of the invention to so coordinate the boiler and the water walls of a water tube lined boiler furnace as to secure effective and improved circulation throughout the system as a whole.

The foregoing, together with such other objects as may hereinafter appear, or are incident to my invention, I obtain by means of a construction which I have illustrated in the preferred form in the accompanying drawings of which Fig. '1 is a vertical section through a boiler and furnace embodying the invention; and

Fig. 2 is a fragmentary cross section taken on the line 2 2 of Fig. 1.

Referring now to the drawings. the reference character A, in general, indicates the boiler which is preferably of the Stirling type, and' the reference character B denotes the furnace or combustion chamber for irin the boiler.

gfhe boiler has three upper steam and water drums, namely, a front drum 7, a middle drum 8, and a rear drum 9; and a mud drum 10 and the three banks of tubes a, b and o suitably baffled to provide three passes. The bank of tubes c are downcomers connecting the rear druln 9 with the mud drum 10; the bank of tubes b are risers connecting the mud drum with the middle drum 8; and the bank of tubes a are risers connecting the mud d'rum 10 with the front drum 7 and the middle drum 8, in which connection it will be observed that certain of the tubes of BOILER AND FURNACE 1927. serial No. 199,902.

l11 and steam tubes 12.`

Referring to the combustion chamber, it is provided with a rear or bridge wall 13extend'ing downwardly from the mud drum; side walls 14 extending upwardly to the steam and water drums; and the front wall 15, the upper portion 15 of whichl is set inwardly to provide a relatively restricted throat 16 through which the gases travel for ultimate passagel over the top of the bathe 17 into the second pass of the boiler. The restriction in the throat isprovided to compensate for the shrinkage in volume of the gases leaving the combustion space proper due to the absorption of heat therefrom. The combustion chamber is, of course, provided with an ash' pit 18.

The combustion space proper has its side walls lined with upright finned tubes 19 cooperating to form a substantially continuous water cooled metallic wall. These tubes are arranged in two groups e and f. The

.walls for connection into the header 21. The

tubes of the group of tubes f lead from the header 20 upwardly to about the level of the mud drum where the pass outwardly through the side walls orconnection with the header 22. The header 21 is connected to the front drum 7 by a number of risers 23, and the header 22 is connected with thefront drum 7 by the riser. or risers 24. The header 20 is supplied with water by a number of downcomers 25 which lead from the/,mud drum 10. It will be understood that both side walls of the combustion chamber have the same arrangement.

Extending across the lower portion of the combustion chamber above the ash pit 18 is a row of relatively widely spaced tubes 26 which have their forward and lower'ends connected with a header 27. The header 27 is supplied with water from the lower drum 10 by means of the downcomer 28. The rear ends of the tubes 26 extend through the bridge wall for connection-by means of junction blocks or yends being connected into the steam and water drum 7*. There is a row of these tubes 30, and it will be seen that the upper'portions thereof lie in advance of the bank of tubes a. Those portions of the tubes 30 immediately in advance of the bridge wall 13 are provided with fins 31 so that, in effect, the bridge wall is covered by a substantially continuous metallic water vcooled wall.

The powdered coal is introduced through the front wall about mid-way of the height of the portion 15 thereof by means of a burner or burners C, which burners are of a construction adapted to produce a-mushroom -shape d flame, such as indicated. With such a type of burner, the powdered coal is substantially completely burned within the combustion space proper, with the hot gases of combustion rising upwardly through the throat 16. The side walls are protected by the groups of tubes@ and f, and also by the cooling effect of those portions of theV boiler tubes near the mud drum. The rear wall of the combustion chamber is protected by the tubes 30. The Gravitating refuse particles are cooled when passing downwardly into the ash pit between the tubes 26.

The side wall tubes, the rear wall tubes,A

the screen tubes 26, all being subject to radiant heat, transmit heat at a very high rate, and evaporate a relatively large quantity of steam. This steam and some water is discharged into the front drum 7. To prevent loading of this drum and to secure better circulating conditions throughout the boiler, certain of the tubes of the front bank a are connected to the middle drum 8, as hereinbefore described. The tubes 30 also serve to relieve the tubes 26 of steam, preventing the burning out of such tubes. of the side wall tubes, the screen tubes, and the tubes 30 with the mud drum ensures rapid lcirculation throughout the system, and thus the capacity of the latter is additionally increased, so that with a comparatively small installation a relatively high capacity is ensured.

The violent and intense' combustion of the fuel with a relatively s hort flame cooperates to secure the high rate of heat transfer and the development of high capacity with a minimum loss in combustible values, which otherwise would be great, because of the coming in contact with the boiler tubes of unconsumed combustible gases. In turn, the side walls and rear wall tubes cooperate to pre-- vent the destruction of the refractory walls which would otherwise ensue where such type of combustion 1s employed.

The connection the presence of the large area of tubes subject to radiant heat, the air for combustion is preheated by means of the preheater D located in the b 'oiler oiftake. The fuel and flame stream is also 'subjected to radiant heat from the refractories of the front Iwall which aids in securing ignition and sustaining the completeness of combustion.

I claim In combination, a Stirling boiler having three steam and water drums anda mud drum, a bank of tubes connecting the rear steam and water drum with the mud drum, a bank of tubes'connec'ting the mud drum and the middle steam and water drum, a ybank-of riser tubes rising from the mud drum, part of the tubes of said bank connecting the mud drum with the middle steam and water drum' and theJ remainder connecting vthe mud drum with the front steam and water drum, a combustion chamber in front of and below the boiler, radiant he'attubes defining the major portion of the combustion space of said chamber, downcomer means leading water from the boiler for said radiant heat tubes,y and upcomer means therefor connected. to the front' 

